In heating, cooling or ventilation systems it is well known to attach a housing defining a plenum directly to the furnace or other source of flowing air to be distributed within a building. Typically, several ducts are connected to the plenum housing to receive air from the plenum for subsequent distribution to the desired locations. Control dampers in the form of movable blades are often mounted in the ducts themselves to control air flow through the ducts.
Such prior art arrangements can occupy a considerable amount of space. Furthermore, extensive duct work may be required. Fabrication and installation of such systems can be time consuming and expensive.
It is well known to provide motor driven damper blades in the ducts of prior art systems of the type described above. U.S. Pat. No. 5,096,156, issued Mar. 17, 1992, may be referred to and is incorporated herein by reference to illustrate motorized damper apparatus employing a transmission incorporating a decoupling mechanism between a damper blade and the motor powering same. Most motorized dampers, however, employ a direct interconnection between the output shaft of the motor and the damper blade. The subject apparatus may be utilized with either damper construction.